Mirekyara

Even though she's a pony, she lives in Inkanterlot and can transform into a Cephalopone/Squid with her necklace and choker combo. The necklace holds the transformation magic, and since she has two forms she can transform into, her choker crystals act as buttons, allowing her to choose her form. She is the most famous singer in Inkanterlot, and acts as the idol. She loves singing, but also lives a secret life as a spy to fight evil. She uses her music to reform villains, much like the song she was based off of.